Continuous oil-gas process



Feb. 26, 1929. 1,703,506

W. S. 'YARD E T AL CONTINUUS OIL GAS PROCESS` Filed Dec. l, 1924 CLE- Patented Feb. 26, 1929.

UNITED STATES 1,703,506 PATENT oFFlcE. y

WILLISS. YARD AND EARL N. PERCY, F SAN FRANCISCO, CALIFORNIA.

CONTINUOUS OIL-GAS PROCESS.

Application led December 1, 1924. Serial N'o. 753,157.

This invention relates to oil gas manufacture, and particularly pertains to a-eontinnous oil gas process and apparatus.

In localities where crude oil is plentiful,

or where its use is economically advantageous over coal, it is common to manufacture gas from oil for municipal and other purposes, the gas thus produced beingr commonly known as oil gas, as distinguished from coal gas and water gas, although water gas enters largely into the manufacture of modern oil gas. v

A typical oil gas analysis resulting from a present day well known type of apparatus for municipal purposes is l'el'n-esented by the following:

Gallons per M cubic feet of gas The intermittent process oi`,1naking gas embodies two antithetieal ideas-a beating period and the gas making period. During the heating period the temperature ol the apparatus is brought up to the gas making stage, usually' of high incandescence, whether the interior Work of the apparatus is carbon-coated cheekerbrick, or other carboncoated refractory material. lVhen' the apparatus is heated to a suiicient ten'iperature, the apparatus is, of course, tilledwith products of combustion, and it is therefore neeessary to arrest. combustion and purge the apparatus of these products of combustion before entering upon the gas making period. The heating period having come to an end, and the apparatus being purged of the dele.- terious products of combustion, which, of course, are Valueless as an illuminant, o1' as a heating (fas, oil and steam, in a well known n n n n manner, are then lntroduced into the highly heated apparatus; the steam serving the double function of atomizing the'oil and of producing water gas.

The gas from the oil and steam is then passed through theapparatus and fixed, and thence conveyed through suitable washers and serubbers to the holders and .mains During thisvgas making period the temperature vof the apparatus is somewhat reduced, due to the atomization of the liquid oil and the introduction of steam, which is of relatively low temperature compared with the interior incandescent temperature of the generator apparatus. As the temperature of the apparatus falls, the gas made changes somewhat both in quality and quantity, as the gas will be relatively thin or lean while the apparatus is at high temperature and relatively rich or heavy as the temperature falls. Y

During this period of temperature drop in gas making by the usual intermittent method, the generator brick cools somewhat and it then becomes necessary to discontinue the` gas making period and again air blast i the apparatus.l In this period of reblasting and of ralsmg the mterlor of the generator to the ytemperature of incandescence, the checkerbrick work 1s reheated and the temperature of the apparatus 1s once more raised .to a point creating a favorable condition for gas making, after which the process de.-

scribed is repeated. This is what is known as intermittent process of making gas from oil.

l Mei/loll of making producer gas.

' products of combustion will be CO. H2, distilled hydrocarbons, a.' certain amount of CO, and nitrogen.

This is the gas usually referred to as pro-v ducer gas. This gas has an 4average calorific value of 150 B. t. u. per Cubic foot 'and is useful only for industrial purposes, being worthless for domestic uses, because of, thel enormous distributing system necessary and the low temperature of the flame.

We have referred to producer gas because in our practice we have made use, for matters of convenience, of a gas producer in our apparatus, although manifestly, our process is not necessarily limited to an initial form of producer gas, as such.

lt will be understood that acceptable commercial gas for industrial and domestic use has been more or less standardized between 4Q() and 600 B. t. u. per cubic foot, because gas within these limitations burns acceptably in industrial and domestic appliances, and also because such gas maybe transmitted economically through the usual. distribution systems.

In the present invention we have aimed to produce an apparatus in which the gasv fore to a continuous oil gas making processy which we consider an improvement over the customary intermittent methods of oil gas making'. More especially, the process relates to the continuous generation of a mix- .ture of oil gas and producer gas by the decomposition of oil in a producer, the deposit ofcarbon from the oil in the producer, the supplying of additional heat necessary by preheating the air used in the producer and the fixing of the vapors and gases in a checkerwork secondary chamber which supplies the necessary contact surface tor ,thc

reactions and heat exchanges among the gas constituents, said reactionsbeing energized by the heat in the gases and preheater.

Our process realizes all the :ulvantages of continuous operation, such as, continuous .maintenance of optimum conditions, minimum of attention necessary, great reliability, iexibility of gas production and gas quality, accurate adjustment of the plant .to the current needs for gas, reduction in sizes of purifiers and scrubbing-equipment, elimination of smoke or objectionable fumes, elimination of lampblack together with a minimum production of tar, 'and a controllable production of hydrocarbon oils.

In addition to the above advantages, pe-

euliar to continuous operation, we realize a very great economy; for example, a 500 B. t.'u. gas has been produced with not more than four and one-half gallons of 16 degrees Baum gravity, heavy fuel oil per thousand cubic. feet, without production of lampblack or naphthalene. This represents asaving of two or two and one-half gallons per lows vertical section view of the mechanism for:

injecting oil into the producer. Figure 3 shows a section taken on the line 3-3 of Figure 2. l

, Referring more particularly to the drawing, the apparatus consists of a blower 10, here indicated as a rotary blower which is connected with an air inlet pipe 11. The air inlet pipe 11 is provided with two connections, a portion 12 extending through a valve 13 to an air preheater 14, and a pipe 15 connor-ted with a valve 16 and controlling the flow of air lto a pipe 1"' through which the air may by-pass the prehea-ter and directly enter the top of a. producer 18. This producer is an apparatus commonly understood as being used in making producer gas.

The preheater 111 is iitted with afirebox 19 supplied with a suitable source of heat, as the oil burner 20. A hot alr conduit 21 is connected with the preheatcr and con-- ductsa .stream ot air to the bottom of thel producer where it passes into the producerA through an inlet 22 having a hood. This hood is covered by a bed of carbonaceous `material as indicated at 23. The top of the Vary chamber is formed with a side wall 30 of refractory material and is preferably iilled with checker-brick work, as indicated at 31, it being understood that during the operation of the apparatus this checkerbrick will be raised to a temperature suliicient to produce incandescence. A gas offtake 32 is connected with the top of the secondary chamber 29 and is in communication with a draw-olil pipe 38 leading to a Washbox 34. The Washed gas may then be conveyed to the suitable. storage .receptacles through a pipe 35 while the sludge and other residue may pass olf from the washbox through trap 36. A f

The operationof the apparatus is as folwith oil carbon, lampblack, charcoal, a'nthracite coal, or other suitable fuel, atire is The producer V18 being half-filled' started. This fire is then blasted with air from the blower 10 and steam delivered through pipes 37 or 38 until producer gas is formed. Secondary air is then admitted through valve 16 and pipe 17, thus supporting combustion of the producer gas and carrying the flame over into the checkerwork chamber 31 oi" the secondary chamber 29, the checker brick of which begins to rise in temperature. This process is carried on until the temperature of the checker-work 3l in practice approximates 1,000o to. 1,S00 Fahr., according to the quality of gas desired. Then the flowv of secondary air entering the producer 18 through pipe 17 is discontinued and the oil is injected into the producer through pipes 27.

In the meantime the burner 20 under the prcheater 14; maintains a suiticient temperature to insure that the injection of oil through pipes 27 does not reduce the temperature of the checkerhrick Cil. then these conditions are balanced and established, van acceptable grade of raw, unvvashed commercial gas issues from the oftake pipe 32 in a continuous flow of Vuniform quality until the plant is closed down. Control of temperatures -in the producer 18 is maintained by controlling the temperature of the ingoing air through the preheater 111. These temperatures may also be controlled by varying the amount of steam admitted through pipes 37 and 38. but this will alter the quality of the. gas. It will be understood that alterations of temperature also lchange the quanti ty ofgas. The steam may be admitted at any stage in thel operation, inasmuch as this is a continuous system.

The quantity of gas is controlled by varying the speed of theair blower 10 and then varying other conditions proportionately in order to maintain the same temperature in the checkerbrick 8l and the same quality ol` gas. The steam and oil are, of course, varied proportionately willi the amount of air.

The amount of. sensible heat developed in a.- producer is easily calculated and Well known to those skilled in the art. This sensible heat is not enough to gasify the necessary amount of oil to enrich the producer gas and raise its calorilic value from approximately 150 B. t. u. to the 400 or 600 B. t. u. of: acceptable commercial gas.

We are therefore supplying this additional heat asV previously described by preheating the air. Thisl preheater may be heated With oil, solid fuel, Wood, lampblack,

tar, gas, or Waste heat. In practice, We use gas and Waste heat, since the efficiency of the plant exceeds eighty percent. and a gas tire requires a minimum of labor.

It is to be understood that steam may or may not be admitted to the producer, and may or may not be preheated. In fact,

i i Per tent l i i l i Without pieheatmg i 375 j 50 250' Fahr 400 4U 45() 35 500 30 500 25 The oil is injected into the top of the producer througha multiplicity of nozzles connected with the manifold 25 by pipes 27. IVe are aware of expcrin'ienls ot' this kind which in most instances have failed because the oil, .if atomized, Will form lampblack and soot; it' injected continuously at one spot, it will extinguish combustion and `gradually soak to the bottom of the pro' ducer. After experiencing'this ditliculty in practice, ive use a multiplicity of nozzles, injecting the oil through a portion of them only and periodically changing from one portion to another portion.

The net result is that We can accurately control the depth to which the oil and its vapors penetrate into the producer. 'Ihe oil deposits carbon in the producer, which is acted upon by the air exothermically and the steam endothermically, forming pro-l ducer gas having considerable sensible heat. 'lhe .sensible heat,` originating in the producer combustion and in the preheater, vaporizes and cracks the oil.

0f course, this carbon bed requiresl theI usual attention of'any producer fuel bed to prevent channeling and caking.' This attention is afforded in our ease by hand poking in the experimental pla-nt, but we contemplate standard automatic mechanical agitating devices for commercial plants.

In addition to the usual attention demanded by all producers, our producer forms cakes of pure carbon under each burner. These cakes must be broken up and separated to preventfuel bed channeling and plugging, resulting in the production of a poor quality of gas. We find these cakes amenable to hand poking and standard mechanical agitation. l I

In other Words, carbon ,is deposited` the oil, and the fuel bed'is continuously replenished by the carbon from the oil.

This carbon is at first in the form of free then cokes under each burner and finally forms a solid disk of coke across the top of the fuel bed, unless this surface is agitated or broken up by suitable poking, either mechanical or by hand.

lVe Wish to emphasize the three stages of carbon formation in the producer, and the stages of treatment .Without which such producers are inoperable when reduced to practice.

First--Deposit of free carbon and oil.

Second--Cokinfr and 'agglomeration of free carbon and o1l.

'Ihird-Breaking up of cbke in suitably sized lumps by poking. s

1f oil only is used in producer, the fuel bed gradually increases.

If steam also is used, this increase is lessened and the fuel bed may then i be caused to decrease in height by the use of sufficient steam.

The resulting producer gas, oil vapors and oil gas contain sufiieient heat to completely ,crack and gasify the oil vapors, but surface contact and time are needed to cause this reaction. Ve do not know whether it is due to catalytic action, adsorbent action, -absorbent action, or exothermic transfer of heat from gas reactions to the brick and endothermic labsm-ption of heat by other reactions from the brick;

butvwe do know from practice that surface contactcompletes the reactions and converts the mixture of vapors and gases into acceptable commercial gas, and this without the addition of further heat than is already contained in the gas, provided the brick or other contact surface is lirst heated to, or above the optimum temperature for the gas desired.

lVe have also found a decided tendency for the gases and vapors to stratify and for the heavy vapors' to-sink to the surface of the fuel bed, or to the bottom of the checker work chan'iber. For this reason We obtained .better results 'by having the gases and vapors at l1 enter the bottom of the checker chamber 31, because they tend to remain until properly cracked. to a lower specific gravity. On the other hand, our experiments which enter the gas at the top of the checker chamber 31 showed a decided tendency for the heavy vapors to drop through the checker chamber without complete cracking. Nor would succeeding uptake chambers remedy matters much because of the falling heat gradient and the necessity of cracking the vapors with initial high heat instead of succeeding lower lpoints on the best gradient. If, however,

the flow of gas from the 'producer and through the secondary chamber is in a generally upwardly direction, as shown on the drawing, it may then be followed by succeeding checker chambers because the initial cracking has been suilicient to eliminate the tendency to stratify. y

We find one or more checker chambers to be advantageous because of their tendency to bring the gas to exact, unvarying standards after the optimum conditions have been obtained.

In our experiments we have found in a general Way that high temperatures produce gases high in hydrogen` low in B. t. u. and a by-product of lampblack. Low temperatures, in a gene-ral way, tend to produce gases high in hydrocarbons and of high '13. t. u. with a by-product of tar. Stilllower temperatures produce a minimumof gas and a maximum ot' cracked hydrocarbons containing benzol and other light hydrocarbons, including a large percentage of unsaturates.

We therefore consider our process a new and novel means for the cracking of oil into lighterhydrocarbons; We consider that this is a useful phase of our invention because great temperature is available for the cracking' of hydrocarbons and we therefore contemplate a further investigation of this phase of our process, and include this phase in our claims. lV'e coi'ltemplate carrying our investigations of this phase into higher pressures for the purpose of reducing the percentage of unsaturates by the well known process of equilibrium and the tendency of hydrocarbons, to crack to saturates rather than unsaturate-s under optimum pressures and temperatures.

We will state that commercial gas, or liquid hydrocarbons can bemade With a downdrop ,checker chamber, but not so efficiently as with an uptake checker chamber. Therefore, While we prefer an uptake checker chamber, We do not confine our process to an uptake chamber, although We obtain more eficient results with an uptake checker chamber and obtain gas which has less illuminants and morey methane. However, we do not claim the injection of oil into a producer broadly.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A method of making oil gas mixed with producer gas in an oil carbon gas producer, which consists in maintaining a deep bed of fuel in the producer at incandescence by admission of air thereto, introducing oil periodically'and successively into said producer at a plurality of iixed points above the fuel bed to thereby continuously replenish the fuel bed successively in different parts of the fuel bed by the deposition of carbon formed by the cracking and distillation of oil in producing the oil vapor and gas, and controlling the oil being deposited successively upon different parts of the fuel bed so that the fuel bed will be uniformly 'replenished llt) while maintaining the optimlm temperature to thereby continuousl replenish the'fuel within the producer Y bed thereof 'by the eposition of carbon 2. Amethodof making oil gas mixed with thereon formed b the cracking and dis- 15 producer' gas in an oil carbon gas producer tillation of oil in orming the oil vapor and 5 which consists in maintaining a, deep bed o gas, whereby the fuel'bed will be replenished ffl'lel in they producer at incandenscence by successively in spots without 'interfering admission of preheated air thereto, .introducwith 'the maintenance of an optimum tem. ing oil periodically and successively' 4into peraturewithin the producer, and thereafter 20A said producer through a plurality of fixed delivering the gas produced to a fixingv 10 openings above the fuel bed, and controlling chamber.

the introduction of oil whereby only a vpor- WILLIS S. YARD. tion of the fuel bed will be treated at a time EARL, PERCY. 

